#include <iostream>

using namespace std;

int main(void)
{
	int days;
	int num = 1;
	int i;
      	cout << "days: ";
	cin >> days;
	for(i = 1; i < days; i ++)
	{
		num = 2 * (num + 1);
	}	
	cout << "number: " << num << endl;

	return 0;
}
